Automatic food tray cleaning machine

ABSTRACT

An apparatus defining a receiving station and a remote discharge station between which high pressure cleaning solution and rinse solution spray jets are spaced both in uppper and lower reaches extending along a path connecting the receiving and discharge stations. The apparatus includes a conveyor extending between the two stations with its inlet end at the receiving station and its outlet end at the discharge station. The conveyor includes structure for (1) engaging horizontally disposed trays sequentially advanced horizontally toward the receiving station, (2) swinging the trays to front-to-rear inclined positions, (3) conveying the inclined trays to the discharge station along a path disposed between the upper and lower reaches in which the spray jets are disposed, and (4) then swinging the trays to inverted horizontal positions from which they are automatically released for horizontal movement from the discharge station.

United States Patent [191 Kraeft [4 Oct. 30, 1973 1 AUTOMATIC FOOD TRAY CLEANING MACHINE [76] Inventor: Robert W. Kraeft, 10581 East Dorado Ave, Englewood, Colo. 1

[22] Filed: Apr. 5, 1971 21 Appl. No.: 131,301

[52] US. Cl 134/46, 134/48, 134/62, 134/199 [51] Int. Cl. B081) 3/02 [58] Field of Search 134/46, 48, 62, 72, 134/131, 199

[56] References Cited UNITED STATES PATENTS 2,644,473 7/1953 FOX et a1 134/46 X 2,884,935 5/1959 Fox 134/72 2,302,730 11/1942 W00lf0l'd..... 134/72 3,675,665 7/1972 Sadwith 134/46 Primary ExaminewRobert L. Bleutge Attorney-Mawhinney & Mawhinney [57] ABSTRACT An apparatus defining a receiving station and a remote discharge station between which high pressure cleaning solution and rinse solution spray jets are spaced both in uppper and lower reaches extending along a path connecting the receiving and discharge stations. The apparatus includes a conveyor extending between the two stations with its inlet end at the receiving station and its outlet end at the discharge station. The conveyor includes structure for (l) engaging horizontally disposed trays sequentially advanced horizontally toward the receiving station, (2) swinging the trays to front-to-rear inclined positions, (3) conveying the inclined trays to the discharge station along a path disposed between the upper and lower reaches in which the spray jets are disposed, and (4) then swinging the trays to inverted horizontal positions from which they are automatically released for horizontal movement from the discharge station.

9 Claims, 9 Drawing Figures PATENTEBnmso I975 MENTOR ROBERT WKRAEFT ATTORNEYS PAIENIEDmnsoum sum 3 or 4 INVENTOR ROBERT W KRA EFT ATTORNEYS rmmmncrsown 3.7sa;49s

' SHEET 40F 4 FIG.6

INVENTOR ROBERT W. KRAEFT ATTORNEYS AUTOMATIC FOOD TRAY CLEANING MACHINE The tray handling and washing apparatus of the instant invention is constructed in a plurality of sections joined together so as to form a horizontally elongated machine. The machine includes a tray receiving station at one end and a tray discharge station at the other end. At the inlet end of the machine there is provided means for horizontally advancing horizontally disposed trays toward the tray engaging and support structure for receiving, engaging and elevating the advanced trays into positions inclined slightly relative to vertical positions and spaced closely apart for subsequent movement toward the discharge station or end of the machine. As the inclined trays are moved toward the discharge end of the machine cleaning solution, rinse solution and final rinse spray jets spaced both above and below the path of the movement of the trays toward the discharge station act upon the trays to wash and rinse the same. After the trays have passed through the area of the machine occupied by the spray jets, the trays approach the discharge station in which the trays are tilted forwardly and downwardly in inverted position and released upon a driven horizontal roller conveyor portion of the machine for advancement away from the tray engaging and support structure after which the trays are passed through a subsection or station in which water clinging thereto is wiped therefrom by squeegees. Other tray drying structures may also be provided if desired before final discharge of the trays from the machine for reception upon a self leveling platform of a tray cart at the final tray outlet of the machine.

The machine is substantially fully automatic in that its tray engaging and supporting structure is operatable to support the trays during their movement passed the spray heads and the pumps which supply cleaning fluid and pre-rinse water to the spray heads are maintained active. The entrance of a tray into the tray receiving station automatically controls the operation of the tray engaging and support structure as well as the final rinse spray jets.

The main object of this invention is to provide an automatic tray washing, drying and stacking machine which will be operative to subsequently receive trays horizontally advanced theretoward, engage the trays, support the trays in optimum position for movement past spray heads for simultaneously cleaning both the upper and under sides of the trays, and then returning thetrays to horizontal position, releasing the trays and discharging the trays from the machine in a horizontal direction for stacking upon a self leveling platform of a tray cart.

Another object of this invention, in accordance with the immediately preceding object, is to provide a tray cleaning machine which will be operative to sequentially receive, engage and support trays to be cleaned at a speed greater then the speed of a horizontal feed conveyor associated with the machine and thereafter horizontally advance trays toward the receiving end of the machine. I

Still another object of this invention is to provide a machine in accordance with the preceding objects and which will be substantially automatic in operation so as to provide a device that will not require an operator therefor in accomplishing an efficient and economical tray washing, drying and stacking machine.

With the foregoing and other objects in view, the invention will be more fully described hereinafter, and will be more particularly pointed out in the claims appended hereto.

In the drawings, wherein like symbols refer to like or corresponding parts throughout the several views:

FIG. 1 is a side elevational view of the tray washing, drying and stacking machine of the instant invention with portions of the enclosure panels of the side thereof in the foreground being broken away to more clearly illustrate the internal structural details of the machine;

FIG. 2 is a fragmentary enlarged end elevational view of the tray receiving end of the machine illustrating the manner in which guides are provided for properly positioning of the trays advanced into the machine for engagement by the tray conveyor assembly of the machine;

FIG. 3 is a fragmentary top plan view of that portion of the machine illustrated in FIG. 2;

FIG. 4 is a schematic view on somewhat of an enlarged scale of the inlet end of the tray conveying assembly of the machine;

FIG. 5 is a further enlarged schematic view of the tray discharge end of the tray conveying assembly of the machine;

FIG. 6 is an enlarged schematic view comprising a left-hand extension of FIG. 4;

FIG. 7 is an enlarged schematic view comprising a right-hand extension of FIG. 5;

FIG. 8 is a digramatic view illustrating a simplified electrical control circuit for effecting automatic operation of the machine; and

FIG. 9 is a fragmentary side elevational view of the tray discharge end of the machine illustrating the tray receiving cart and the limit switch actuators controlled thereby.

Referring now more particularly to the drawings, the numeral 10, generally designates the tray washing, drying and stacking machine of the instant invention. The machine 10 is horizontally elongated and includes an inlet or tray receiving end 12 and an outlet or tray discharge end l4.- Further, the machine 10 includes an elongated sectional frame structure referred to in gen-' era] by the reference numeral 16 which extends from the inlet end .to the discharge end thereof and various components of the machine 10 to be described more fully hereinafter, with the exception of the tray cart generally referred to by the reference numeral 18 at the discharge end 14 of the machine 10, are supported from the frame 16. I

A plurality of horizontally aligned and transversely extending infeed rollers 20 are disposed at the inlet end of the machine 10 and driven from an electric motor 22 by means of a main toothed belt 24 and a plurality of.

secondary toothed belts 26, see FIG. 1.

A tray support conveyor assembly generally referred to by the reference numeral 28 is also provided and includes a pair of opposite end shafts 30 and 32 supported from the frame 16. The shafts 30 and 32 each have a pair of axially spaced sprocket wheels 34 mounted thereon and corresponding sprocket wheels mounted on the shafts 30 and 32 are aligned. A pair of endless flexible link-type members 36 are trained about the pairs of corresponding sprocket wheels 34 and the members 36 include longitudinally spaced pairs of transversely aligned abuttment members 38 thereon. The abuttment members 38 are supported from every other link 40 of each of the members 36 and the shaft 30 includes a cam wheel 42 mounted thereon provided with six equally circumferencally spaced cam members 44 which extend generally radially outwardly from the shaft 30, see FIGS. 3 and 4. The cam wheel 42 is spaced generally centrally intermediate the sprocket wheels 34 on the shaft 30 and the shaft 32 also includes a similar cam wheel 46, see FIG. 5, provided with six equally circumferentially spaced cam members 48 thereon which also extend generally radially outwardly from the shaft 32.

The shaft 30 has a pulley wheel 50, see FIG. 1, mounted thereon and the pulley wheel 50 is aligned with a drive pulley 52 of an electrically actuated single revolution clutch 54. The drive pulley 52 is drivingly connected to the pulley wheel 50 by means ofa toothed belt 56 and the single revolution clutch 54 is driven from a drive pulley 58 through a toothed belt 60. The drive pulley 58 is driven by an electric motor 62.

The discharge end 14 of the machine includes a plurality of rollers 66 similar to rollers 20 driven from an electric motor 68 through a toothed belt 70. The rollers 66 are also drivingly connected by means of toothed secondary belts 72 and it will be noted that the rollers 20 and 66 rotate in clockwise directions as viewed in FIG. 1 of the drawings.

The mid portion of the machine 10, generally centrally intermediate the receiving and discharge ends 12 and 14 thereof, includes a first intermediate section 76 having upper and lower manifolds 78 and 80 disposed therein supporting upper jets 82 and lower jets 84 therefrom. The upper jets are directed downwardly and are spaced considerably above the upper reach of the member 36 and the lower jets 84 are upwardly directed and displayed closely beneath the upper reach of the member 36. The manifolds 78 and 80 are communicated with the interior of a pressure pipe 86 leading from the outlet 88 ofa pump 90. The pump 90 is driven by an electric motor 92 and the pump 90 includes an inlet 94 and a drain line 96 is provided for pump 90 controlled by a dump valve.

The machine 10 also includes a second intermediate section 98 adjacent the discharge end 14 of the machine 10 and the section 98 is similar to the section 76 in that it includes upper and lower manifolds 100 and 102 including spray jets 104 and 106, respectively. The manifolds 100 and 102 are communicated with a pressure pipe 110 which leads from the outlet 112 of a second pump 114 driven by an electric motor 116. The pump 114 also includes an inlet 118 and the drain line 96 is also communicated with the pump 114 through a second dump valve.

A final rinse pipe 115 having a solenoid valve 117 disposed therein is also communicated with the pressure pipe 1 10 at its inlet end. The pipe 1 serves to deliver final rinse water to upper final rinse jets 119 as well as the transversely spaced lower final rinse jets 121. Accordingly, it may be seen that the third section of the machine includes not only the lower rinse jets 104 and 106 but also the final rinse jets 115 and 121.

The intermediate sections 76 and 98 include fluid collecting means 120 and 122, respectively, including outlets 124 and 126 for return of the fluid discharge from the spray jets in the sections 76 and 98 to the pumps 90 and 114.

With attention now invited more specifically to FIGS. 2 4, 6 and 8 of the drawings it may be seen that the inlet end 12 of the machine 10 includes a pair of adjustable opposite side tray guides 130 which function to guide and center the trays on rollers 20. In addition the inlet end 12 includes a first electric eye 132 and a second electric eye 133. The electric eye or photoelectric switch 132 is connected, through an integral relay, to two time delay relays referred to by the numerals 131 and for controlling the operation of the latter. The photoelectric switch 132 is initally actuated upon the entrance of a tray into the tray receiving end 12 of the machine 10 along the rollers 20. Actuation of the photoelectric switch 132 closes the integral relay (not shown) which in turn energize timing relays 131 and 135, such as an Agastat timing relay of the 2400 series which controls a preset time the contacts of the relay remain open or closed when energized. Through the open contacts of timing relay 131 (when energized) the solenoid of the single revolution clutch 54 remains deenergized. As a tray such as tray 134 continues to be advanced forwardly into the receiving end of conveyor assembly 28 of the receiving end 12 of the machine 10 by means of the rollers 20, the tray 134 moves out of registry with the photoelectric switch 132 deenergizing the solenoid of the timing relay. The contacts however remain in the energized attitude until the preset time has elapsed, which maintains the solenoid of the single revolution clutch 54 in a de-energized state. The preset time of the timing relay 131 is sufficient to allow the tray 134 to advance forwardly on rollers 20 to actuate photoelectric switch 133 which is connected directly to the solenoid of the single revolution clutch 54, therefore energizing the solenoid which lifts a trip lever allowing the clutch to engage. The single revolution clutch 54 drives the shaft 30 through a six to one reduction ratio defined by the drive pulley 52, the pulley wheel 50 and the belt 56. Thus, the shaft 30 is rotated one sixth of a revolution and points C on the abuttment members 38 disposed beneath the tray 134 lift the tray from opposite sides thereof with the forward edge of the tray engaged with cam surface D to prevent the tray 134 from falling out of engagement with the conveyor assembly 28. When the cam member 44 behind the tray 134 moves out of registry with the second photoelectric switch 133, the single revolution clutch 54 is deenergized thus again stopping the conveyor assembly 28. The preset time, on timing relay 131 controlled by the photoelectric switch 132, elapses shortly after the single revolution clutch 54 has completed its revolution stopping the conveyor assembly 28. The contacts of timing relay 131 close energizing the solenoid of the single revolution clutch 54, also simultaneously energizing the solenoid of timing relay 131 thus a continuous repeating cycle is established until the next tray 134 enters the machine which repeats the previously mentioned sequence. The continuous repeating cycle assures the complete processing of a single tray 134 or trays 134 entering the machine at irregular intervals.

At this point, it is believed advisable to further set forth that if a second tray 134 registers with the photoelectric switch 132 prior to the elapse of the preset time delay of timing relay 131 the time delay period is restarted. Further, a second time delay relay 135 is provided and also actuated by the photoelectric switch 132 and actuates the solenoid valve of the final rinse line thus the spray heads or nozzles 119 and 121 so that the trays 134 being conveyed along the upper reach of the conveyor assembly 28 will be acted upon by the spray nozzles. When the tray 134 advances beyond the final rinse area along conveyor assembly 28 the preset time delay of the timing relay 135 elapses de-energizing the solenoid valve closing the final rinse line thus conserving the fresh water consumption.

The fresh water spray heads or nozzles direct the spray pattern from above and below similar to the recirculated wash and pre-rinse spray heads or nozzles. However the water is not recirculated. The final rinse line is connected directly to a fresh water supply line.

As the trays 134 are elevated to the slightly inclined positions in which they are conveyed along the upper reach of the members 36, the cam point E releases the tray and the tray is then held back by the back of the leading abuttment member 38. Then, cam surface F pushes the tray 134 forward against the leading abuttment member 38 to assure that the tray 134 will be disposed in the proper slightly declined angle whereupon the upper nozzles 82 and 104 and the lower nozzles 84 and 106 will be able to discharge fluid downwardly upon the upper surfaces of the tray and upwardly against the under surfaces of the tray, respectively.

As the trays 134 are conveyed toward the outlet end of the conveyor assembly 28, the trays are swung forwardly and downwardly and pitched forward by points A of the cam members 48. Points B of the cam members 48 and points G of the abuttment members 38 hold the trays 134 in position until the tray comes into contact with the driven rollers 66 at which time the trays 134 are released from engagement between the abuttments 38 and the cam members 48 and horizontally advanced forwardly toward the tray cart 18 in inverted position for discharging on the self-leveling platform 136 of the cart 18. The platform 136, counterbalanced by springs, lowers the trays 134 stacked thereon. When lowered to its full extent, the platform 136 engages in a first limit switch 138 to open the latter and terminate the operation of the machine 10. When the cart 18 is removed for transporting the inverted trays 134 thereon to a remote location, the limit switch 138 is released. However, the limit switch 138 controls the electromagnetic holding type starter and will not again close to actuate the machine until an empty cart 1 18 is again properly positioned at the discharge end 14 of the machine 10 in order to close a second limit switch 140 which was opened .upon the removal of the full tray cart 18. Thereafter the start switch 141 of the machine 10 may be momentarily closed to again actuate and thus close the magnetic holding type starter.

The photoelectric switches 132 and 133 may be of the single-unit reflex control type, series 42RL manufactured by the Electronic Corporation of America. In addition, the single revolution clutch 54 may be of any standard type such as that covered by the US. Pat. No. 2,140,737 and manufactured by the Hilliard Corporation of Elmira, New York.

Because of the precise positioning of the trays 134 in slightly inclined positions, the trays may be closely spaced along the upper reach of the member 36 and yet still be fully acted upon by the upper jets 82 and 104 as well as the lower jets 84 and 106. It is also to be understood that the infeed rollers 20 serve to speed up forward advancement of the trays 134 into the receiving end 12 of the machine 10 and that the sequential operation of the single revolution clutch 54 is such that the trays 134 are engaged, picked up, and moved out of the horizontal position of the tray 134 illustrated at the left hand side of FIG. 4 so that the shaft 30 may rotate its one sixth of a revolution for proper positioning to receive the next tray 134 before the next tray 134 may be moved into position. Accordingly, there is no jamming of the trays 134 at the receiving end 12 of the machine 10. In addition, in as much as the member 36 is intermitently advanced and the shafts 30 and 32, when stationary during non operation of the conveyor assembly 28 are positioned correctly for receiving a tray 134 at the receiving end 12 of the machine 10 and discharging a tray 134 from the discharge end 14 of the machine 10, the pick up of the trays 134 at the inlet end of the machine and the discharging of the trays 134 from the tray discharging end of the machine is accomplished smoothly and with sufficient delay in actuation of the conveyor assembly to enable the full correct positioning of an incoming tray 134 at the inlet end of the machine 10 and full discharging of a tray 134 for the conveyor assembly 28 at the discharge end of the machine 10.

With attention directed now more specifically to FIG. 7 of the drawings it may be seen that the discharge end of the machine 10 includes upper and lower squeegee assemblies referred to in general by the reference numerals 142 and 144, respectively, which are operable to wipe fluids clinging to the upper and lower surfaces of the inverted trays 134. In addition, the discharge end 14 of the machine 10 may be elongated and include a drying section in which the trays 134 are subject to drying heat subsequent to their passing through the squeegee assemblies 142 and 144 if desired.

The spray jets provided with water from the pumps and 114 utilize recirculated water or cleaning fluids, water from the jets 82 and 84 passes through removable screens (not shown) and is carried to the collecting means from where the water or cleaning fluids are returned to the pump 90. On the other hand, rinse water from the jets 104, 106, 119 and 121 must be maintained and provisions are made whereby fluid loss in the washing section as well as fluid in the rinsing section may be compensated for.

From FIG. 1 of the drawings it will be noted that all four sections of the machine are fully enclosed, the side access doors for the second and third sections of the machine being illustrated removed in FlG. 1. Further, the various electrical components of the machineare of a waterproof or splashed-proof type and noncorrosive materials are utilized in the construction of the machine throughout.

In addition to the above, inasmuch as the cleaning and rinse fluids are recirculated, the spray jets have large unrestricted openings and the various pipes from which the spray jets are supported have removable end caps for easy cleaning. Further, in the event atray jams or fails to leave the machine in a predetermined length of time, a further switch (not shown) in conjunction with a time delay relay (also not shown), senses the presence of the tray and terminates operation of all roller and conveyor systems until that tray is removed and the machine is restarted.

What is claimed is:

l. A tray washing machine including conveyor means for supporting a plurality of trays for movement along an elongated path with the trays spaced slightly apart along said path and slightly angularly displaced relative to the plane of said path, discharge means operative to discharge cleaning fluid in relatively opposite directions to the top and bottom surfaces of the trays as the trays move along said path in their angularly displaced positions, said conveyor means including an inlet end, intermittently actuatable drive means for driving said conveyor means, said inlet end of said machine including tray receiving means for receiving trays horizontally thereon to be advanced by the conveyor means along said path, tray sensing means operative to sense a tray received by said tray receiving means, said tray sensing means including an operative connection with said drive means to terminate operation of said conveyor means as a tray advances into close proximity to the inlet end of said conveyor means and with said conveyor means positioned in one position of a plurality of predetermined positions thereof, said conveyor means including tray support means spaced therealong by which said trays are supported in inclined position when moved along said path by said conveyor means, one of said tray support means being disposed at the inlet end of said conveyor in each of said predetermined positions of said conveyor means and operative to engage a tray received by said receiving means and thereafter, upon subsequent actuation of said drive means, to lift said tray and displace the latter to said inclined position for movement by the conveyor means.

2. The combination of Claim 1 wherein said tray sensing means also includes means operative, after termination of operation of said drive means, to again actuate said drive means after a predetermined time delay.

3. The combination of Claim 1 wherein said machine and conveyor means include a discharge end disposed at the end of said path remote from the inlet end, said tray support means, when approaching the discharge end of said conveyor means, each including means operative to swing the associated tray to a horizontal position at the discharge end of the conveyor means and for ready release of the tray from the conveyor means upon continued movement of said tray along said path past the discharge end of said conveyor means.

4. The combination of Claim 3 wherein said discharge end of said machine includes tray conveying means for receiving a horizontal tray at said discharge end of said conveyor means and operative to move a tray disposed at the discharge end of said conveyor means from engagement with the latter and further toward said discharge end of said machine.

5. The combination of Claim 3 wherein said conveyor and tray support means also move the tray past the discharge means toward the discharge end of the conveyor means, said tray sensing means also including means operative, after termination of operation of said drive means, to again actuate said drive means after a predetermined time delay, said tray support means, when approaching the discharge end of said conveyor means, each including means operative to swing the associated tray to-a horizontal position at the discharge end of the conveyor means and for ready release of the tray from the conveyor means upon continued movement of said tray along said path past the discharge end of said conveyor means.

6. The combination of Claim 5 wherein said outlet end of said machine includes tray conveying means for receiving a horizontal tray at said discharge end of said conveyor means and operative to move a tray disposed at the.discharge end of said conveyor means from engagement with the latter and further toward said discharge end of said machine.

7. The combination of Claim 6 wherein said tray receiving means includes a first driven roller conveyor and said tray conveying means includes a second driven roller conveyor.

8. A machine for cleaning trays, said machine including first, second and third sections spaced along a predetermined path of movement, said first section including first means operative to support and generally horizontally move horizontally disposed trays along said path toward said second section with said trays disposed in single file relation extending along said path, said second section including second means for sequentially engaging, elevating and swinging the trays advanced thereto from said first section into positions with said trays disposed in closely spaced relation along said path and similarly inclined slightly relative to positions disposed normal to said path, said second means also including means for advancing the inclined trays toward said third section in single file relation past through a predetermined zone of said second section, said zone of said second section including spray outlets spaced along opposite sides of said path and operable to discharge jets of cleaning fluids therefrom in opposite directions toward said path for impingement upon opposite sides of the trays being moved through said zone, said third section including conveying means operative to sequentially receive horizontally disposed trays and to further advance the received trays further along said path, the position of said second section adjacent said third section including means operative to sequentially swing the trays moved through said zone to horizontal positions supported from said conveying means.

9. The combination of claim 8 wherein said second section, in addition to the first mentioned spray outlets disposed therein, includes a second set of spray outlets spaced transversely of opposite sides of said path and operable to discharge jets of final rinsing fluids therefrom in opposite directions towards said path for impingement upon opposite sides of said trays being moved through said zone, the second mentioned spray outlets being disposed downstream along said path relative to the first mentioned spray outlets. 

1. A tray washing machine including conveyor means for supporting a plurality of trays for movement along an elongated path with the trays spaced slightly apart along said path and slightly angularly displaced relative to the plane of said path, discharge means operative to discharge cleaning fluid in relatively opposite directions to the top and bottom surfaces of the trays as the trays move along said path in their angularly displaced positions, said conveyor means including an inlet end, intermittently actuatable drive means for driving said conveyor means, said inlet end of said machine including tray receiving means for receiving trays horizontally thereon to be advanced by the conveyor means along said path, tray sensing means operative to sense a tray received by said tray receiving means, said tray sensing means including an operative connection with said drive means to terminate operation of said conveyor means as a tray advances into close proximity to the inlet end of said conveyor means and with said conveyor means positioned in one position of a plurality of predetermined positions thereof, said conveyor means including tray support means spaced therealong by which said trays are supported in inclined position when moved along said path by said conveyor means, one of said tray support means being disposed at the inlet end of said conveyor in each of said predetermined positions of said conveyor means and operative to engage a tray received by said receiving means and thereafter, upon subsequent actuation of said drive means, to lift said tray and displace the latter to said inclined position for movement by the conveyor means.
 2. The combination of Claim 1 wherein said tray sensing means also includes means operative, after termination of operation of said drive means, to again actuate said drive means after a predetermined time delay.
 3. The combination of Claim 1 wherein said machine and conveyor means include a discharge end disposed at the end of said path remote from the inlet end, said tray support means, when approaching the dischaRge end of said conveyor means, each including means operative to swing the associated tray to a horizontal position at the discharge end of the conveyor means and for ready release of the tray from the conveyor means upon continued movement of said tray along said path past the discharge end of said conveyor means.
 4. The combination of Claim 3 wherein said discharge end of said machine includes tray conveying means for receiving a horizontal tray at said discharge end of said conveyor means and operative to move a tray disposed at the discharge end of said conveyor means from engagement with the latter and further toward said discharge end of said machine.
 5. The combination of Claim 3 wherein said conveyor and tray support means also move the tray past the discharge means toward the discharge end of the conveyor means, said tray sensing means also including means operative, after termination of operation of said drive means, to again actuate said drive means after a predetermined time delay, said tray support means, when approaching the discharge end of said conveyor means, each including means operative to swing the associated tray to a horizontal position at the discharge end of the conveyor means and for ready release of the tray from the conveyor means upon continued movement of said tray along said path past the discharge end of said conveyor means.
 6. The combination of Claim 5 wherein said outlet end of said machine includes tray conveying means for receiving a horizontal tray at said discharge end of said conveyor means and operative to move a tray disposed at the discharge end of said conveyor means from engagement with the latter and further toward said discharge end of said machine.
 7. The combination of Claim 6 wherein said tray receiving means includes a first driven roller conveyor and said tray conveying means includes a second driven roller conveyor.
 8. A machine for cleaning trays, said machine including first, second and third sections spaced along a predetermined path of movement, said first section including first means operative to support and generally horizontally move horizontally disposed trays along said path toward said second section with said trays disposed in single file relation extending along said path, said second section including second means for sequentially engaging, elevating and swinging the trays advanced thereto from said first section into positions with said trays disposed in closely spaced relation along said path and similarly inclined slightly relative to positions disposed normal to said path, said second means also including means for advancing the inclined trays toward said third section in single file relation past through a predetermined zone of said second section, said zone of said second section including spray outlets spaced along opposite sides of said path and operable to discharge jets of cleaning fluids therefrom in opposite directions toward said path for impingement upon opposite sides of the trays being moved through said zone, said third section including conveying means operative to sequentially receive horizontally disposed trays and to further advance the received trays further along said path, the position of said second section adjacent said third section including means operative to sequentially swing the trays moved through said zone to horizontal positions supported from said conveying means.
 9. The combination of claim 8 wherein said second section, in addition to the first mentioned spray outlets disposed therein, includes a second set of spray outlets spaced transversely of opposite sides of said path and operable to discharge jets of final rinsing fluids therefrom in opposite directions towards said path for impingement upon opposite sides of said trays being moved through said zone, the second mentioned spray outlets being disposed downstream along said path relative to the first mentioned spray outlets. 